ff7 and xenogears are the only two PS1 games i've ever seen that cost $50 or more, and if you check other places, or stores for that matter, it's about the same. Gray well, a video game pawn shop here, has a greatest hits copy of FF7, used, for $80. Thats even more than amazon's price.
FF8, 9, chrono cross, the 3 crash bandicoot games, metal gear solid, and a handful of others can each be bought for $20 or less.
Unless your looking for FF7, FFTactics, Xenogears, Lunar2, or something else that obscure, PS1 games are pretty cheap.
And by the way,
Amazon.com: Breakout: Video Games
That game is just plain awesome. Simple but fun. ePSXe plays it perfectly as well.